“How can you believe who receive praise from one another and do not seek the praise that comes from the only God?”
He then questions how they can possibly believe when their main concern is not the praise and glory of God but their own praise and glory. For the truth is that if men are to know the truth they must be wholehearted in their search for it. But these men longed for the praise of their fellowmen and so they lived and believed accordingly. If they had really sought praise from the central source, ‘the only God' (tou monou theou), they would have known the truth about Him. The phrase stresses that they boasted of their belief in the one and only God, and yet looked elsewhere for their praise. They looked to men. They were double-minded. It is thus they who were living independently of God, not Jesus.
The stress is on the fact that there is no value in pretending to love ‘the only God' if their thoughts and obedience are not centred on Him. Those who seek their praise and honour from men demonstrate that it is men whom they love, and whose verdict they desire, not He Who alone is God. They were so eager to get men to live in accordance with their own ideas, that they did not have time to contemplate God and recognise that some of their ideas were wrong. (Which was why the signs passed them by).